FR2481476A1 - MOVEMENT FOR ELECTRONIC WATCH WITH ANALOG DISPLAY - Google Patents

Abstract

In the movement for an electronic watch with analogue display, hand-carrying arbors 20, 22 have pinions 20a, 22a of very small diameter, rather than wheels. The cell 10 has a diameter which is substantially equal to the radius of the movement plate 2, since the cell extends from the periphery of the movement up to the pinions 20a, 22a. The wheels 28, 30, 34, 40, 42 which drivably connect the motor 8 to the pinions 20a, 22a are arranged in such a manner that there is no overlapping between the cell 10 and the wheels. This makes possible a movement which is both of small diameter and thin.

Description

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  MOVEMENT FOR ELECTRONIC WATCH WITH ANALOG DISPLAY

  The present invention relates to a movement for a watch

  electronic display with analogue display.

  More specifically, the present invention relates to an electronic watch movement which comprises at least one battery, a motor powered by the battery, axes minutes and hours and a train of mobiles transmitting the movement of the motor to

  axes, this movement having reduced dimensions.

  It is known that in all analog display electronic watches, the largest component is the battery which provides the electrical energy necessary for the operation of

  the watch. The diameter of these cells, which are generally cylindrical,

  This imposes the size of the motion along the radial direction of the motion that contains the stack. In addition, it is known that the axis of the minute and hour hands which occupy the center of the caliber are associated with wheels, at least one of which

  hours, has a large diameter. As a result, the size

  motion in its radial direction containing the stack

  is imposed not only by the diameter of the pile, but also

  by the radius of the wheel linked to the axis of hours.

  A first solution to keep a reduced radius to the movement of the watch is to have the big wheel hours above or below the stack. It is understood that then one can achieve a circular motion whose radius is substantially equal to the diameter of the stack. On the other hand, this solution increases the thickness of the movement and therefore of the watch, which makes this arrangement practically inapplicable to the case of watches

for lady.

  To avoid this extra thickness, another solution is to give the movement an elongated shape. But that makes impossible the use of a round dressing. But this is often sought

for lady's watches.

  To remedy these drawbacks, a first object of the in-

  vention is to make a movement of electronic watch circulating

  which has a thickness and a reduced diameter.

  A second object of the invention is to produce a substantially circular watch movement of the type previously defined in FIG.

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  -2- which the radius of the movement is substantially equal to the diameter of

the battery.

  A third object of the invention is to realize a movement

  of the previous type in which the thickness of the movement

  is substantially equal to that of the battery.

  These objects are achieved by the invention by virtue of the fact that the projection of the stack on a plane of cross-section of the substantially cylindrical movement and parallel to the axis of the cylinder intersects at least one radius of said cylinder at two points separated by a distance substantially equal to the length of said radius; and that the projections of the motion-transmitting movers and the needle-axis wheels on said plane are located entirely at

  outside the projection of the pile.

  It thus clearly appears that not only can the diameter of the stack be substantially equal to the radius of the movement, but also the thickness of the movement is substantially equal to that of the stack since there is no overlap between the stack and mobiles whether they are mobile or mobile

related to the axes of the needles.

  In any case, the invention will be better understood when reading

  of the following description of several embodiments of

  the invention given by way of non-limiting examples. The description

  refers to the attached figures on which

  in Figure 1, a schematic top view of a movement

  showing the main characteristics of the invention

  FIG. 2 is a vertical sectional view of part of the movement of the watch showing the transmission mobiles between the motor and the axes, and

  in FIG. 3, a partial view in vertical section

  trant movement according to the invention for a watch comprising

a second hand.

  Figure 1 shows, in top view, a simplified watch movement to better show the main features of the present invention. He is represented there

  platinum 2 of circular shape which thus defines the cylindrical shape

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  only movement. This figure also shows symbolically

  that the geometric axis XX of the plate 2 which coincides with the geometric axis axes minutes and hours; It is also symbolized the size 6 of the pinions associated with the axes of the hours and minutes. These cogs will be described later in detail with reference to Figure 2. It is sufficient to know that

  all these mobiles are projected on the plane of the figure on the outside.

  the projection of the stack 10 on the same plane.

  It emerges from this figure 1 that according to the main characteristic of the invention, the stack 10 which is most often of cylindrical shape has a diameter which is substantially equal to the radius of the movement 2. In other words, if one consider the radius R of the movement, we see that this ray intersects the projection of the stack on the plate at two points A and B, these two points A and B being distant by a length substantially equal to the length of the radius R of the movement . As will be explained later, this arrangement is made possible by the adoption of a gear train of a particular type and by the fact that the invention uses for the training of the axis of the minutes and the axis of the hours of the gears of very small diameter. Indeed, it is the diameter of these gears which defines the remaining place for the establishment of the stack 10, if also the overlap of the mobiles

and the battery should be avoided.

  In Figure 2 are shown the plate 2 and a bridge 12 of the movement. In the space limited by these two plates is housed the motor 8 which comprises perfectly known a rotor 8a provided with its magnet 14 carried by the plate 14a. The rotor 8a is extended by a pinion 8b. The pivots 8c of the rotor shaft are mounted in bearings 16 driven in orifices 18 and 18 'respectively formed in the plate 2 and the bridge 12.

  the axis of minutes 20 and the axis of hours 22 which admit-

  As a geometrical axis, the XX axis of the movement. More precise-

  the minute axis 20 is constituted by a floor threaded on a fixed axis 24 integral with the plate 2. The axis 20 is provided with a minute gear 20a. The axis of hours 22 which is hollow and which partially surrounds the minute axis 20 is constituted by a barrel wheel whose pinion is referenced 22a. As is

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  4, the hour and minute hands are respectively mounted on the shafts 22 and 20. It should also be observed that

  between the two shafts is disposed a washer 26 which has a

  The purpose of this is to keep the minute shaft 20 in place when it is necessary to reverse the movement in order, for example, to perform engine torque tests. It should be noted that the pinions 20a and 22a both have an outer diameter equal and that outer diameter is very little different from the outer diameter of the shaft 22. This difference is substantially equal to the tooth height. In other words, the pinions 20a and 22a have a diameter also

  as small as possible. It is therefore understandable that thanks to this

  a distance substantially equal to the length of the radius of the

  movement is available for the implantation of the battery 10.

  FIG. 2 represents a possible embodiment of the mobile train which is able to transmit the movement of the motor 8 to the pinions 20a and 22a of the hours and minutes axes. This train comprises a first intermediate wheel 28 pivotally mounted in bearings comprising a pinion 28a and a wheel 28b engaged with the pinion 8b. This first intermediate mobile meshes with a second intermediate mobile 30 which also comprises a pinion a and a wheel 30b. However, it should be noted that the wheel 30b is mounted on the axis 30c of this mobile via a friction device 32 which allows a reset time of the watch without acting on the engine 8. This second mobile intermediate 30 meshes with the timer wheel 34 which includes a minute wheel 34a and a pinion hours 34b. The wheel 34a minutes is kinematically connected as shown in dotted minutes pinion 20a. The pinion 34b hours is

  connected to pinion 22a of the hour axis by two transmission pinions.

  mission 40 and 42. For example, the wheel 40 is pivotally mounted about an axis 44 constituted by an extension of the plate 2 and the wheel 40 is held on its axis 44 by a pin 46 with enlarged head, this pin being driven in a hole 48 formed in the plate 2. The mounting of the wheel 42 is identical to that

of the wheel 40.

  It is clear that the use of the 40 and 42 return wheels

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  It makes it possible to use axle gears for minutes and hours that have substantially the same diameter, without substantially complicating the gear train. In addition, the wheels 40 and 42 being mounted cantilevered, they occupy only part of

the thickness of the movement.

  Thanks to the provisions of the invention the movement which is circular has a minimum diameter for a given pile diameter. However, the thickness of the movement is not increased by

  no wheel or pinion overlaps the battery.

  Figure 3 shows a part of the movement in the case where it further comprises a seconds hand. According to this embodiment, the movement comprises the axis 22 'of the hours with its pinion 22'a, the axis 20' minutes which is a cannon wheel

  with its pinion 20'a, and the fixed axis 24 'which in this case is hollow.

  The axis 24 'is driven into an orifice 50 formed in an internal bridge

  mediator 52 of Jla's movement shows. Inside the hollow shaft 24 'is mounted the solid axis 54 seconds. This axis passes through the hollow axis 24 'and has at its end a pinion 54a whose outer diameter is substantially equal to that of the pinions 22'a and 20'a. The gear train connecting the motor 8 to the various shafts 20 ', 22' and 54 can advantageously be made in the following manner: a mobile 58 transmits the movement between the pinion 8b of the rotor and the pinion 54a of the second axis. The mobile 58 meshes with the mobile 56, the mobile 56 and 58 being mounted between the bridge

  12 and the intermediate bridge 52. The mobile 56 is connected by the

  intermediate of a mobile not shown to the mobile 34 'which is the equivalent of the mobile 34 of Figure 2. It is mounted between the plate 2 and the intermediate bridge 52. The mobile 34' meshes directly with the pinion 20'a of the axis 20 'and secondly with the two transmission gears 40' and 42 'similar to the gears 40 and 42 of Figure 2 but which are mounted between the plate 2 and the intermediate bridge 52. The pinion 42 'meshes with

pinion 22a of the hour axis.

  In this embodiment, the various elements of the gear train are arranged in such a way that their projection on the plane of FIG. 1 falls outside the projection of the

stack on the same plane.

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Claims (3)

  An analog display electronic watch movement having substantially the shape of a cylinder comprising at least one battery, a motor powered by said battery, a minute hand and an hour hand, axles provided with wheels on which are mounted said needles these axes coinciding with the axis of said cylinder, and motive transmission motions of said motor to the wheels of said needle axes, said movement being characterized in that the projection of the stack (10) on a plane of cross section of the cylinder parallel to said axis (XX) of the cylinder intersects at least one radius (R) of said cylinder at two points (A, B) separated by a distance substantially equal to the length (R) of said radius and in that the projections of said mobiles ( 28,30,34,40,42,34,56,58) and said needle axis wheels (20a, 22a, 20'a, 22'a) on said plane parallel to said axis (XX) of the   cylinder are located entirely outside the said projection said stack (10).   2. Movement according to claim 1, characterized in that said axes (20, 22, 20 ', 22') are respectively internal (20, 20 ') and outer (22, 22') coaxial hollow axes and in that said wheels mounted on said axes are constituted by toothed pinions (20a, 22a, 20'a, 22'a) forming an integral part of said axes (20, 22, 20 ', 22'), said pinions associated with said axes having the same outer diameter, the outer diameter of said pinions (20a, 22a, 20'a, 22'a) only surpassing the outside diameter of the outer axis (22,22 ') than substantially height of the toothing.   3. Movement according to any one of claims 1 and 2, characterized in that said transmission mobiles comprise a first mobile (34) having a minute wheel (34a) meshing directly with the pinion (20a) of the axis of the minutes and a pinion hours (34b), and a set of second mobiles each having only one wheel (40,42) connecting the pinion hours   at the pinion (22a) of the hour axis.